#include <stdio.h> 
int IsPrime(int m){
	int i=0;
	if(m<2){
		return 0;
	}
	for(i=2;i<(m/2);i++){
		if(m%i==0){
			return 0;
		}
	}
	return 1;
	
}
int main(){
	int input;
	scanf("%d",&input);
   int  res = IsPrime(input);
   if(res == 1){
   		printf("%d is a prime number\n",input);
   }else{
   		printf("%d is not a prime number\n",input);
   } 
    return 0;

}

